Zeiss Biogon [I] by Bertele (1934), from US 2,084,309[1]
Wild Aviotar by Bertele (1947), from US 2,549,159[2]
KMZ Jupiter-12 lens
The first Biogon lens (2.8 / 3.5 cm, an asymmetric design featuring seven elements in four groups) was designed in 1934 by Ludwig Bertele[1] while he was working for Zeiss, as a modification of his earlier Sonnar design (1929).[3]: 120 The Biogon was assigned to Zeiss IkonDresden and marketed with the Contax rangefinder camera. It was produced by Carl Zeiss starting in approximately 1937, first in Jena, then a redesigned version was built in Oberkochen.
Bertele would go on to reuse the design for the WildAviotar.[3]: 120 After World War II, KMZ also reused the Biogon design for the Jupiter-12.[4]
Biogon (II), 1951
Biogon (II) and antecedents
SchneiderAngulon by Tronnier (1930), from US 1,882,530[5]
Zeiss Topogon by Richter (1933), from US 2,031,792[6]
Zeiss Biogon by Bertele (1951), from US 2,721,499[9]
Symmetric wide-angle lenses with meniscus elements facing the object and image had been developed in the 1930s, including the Schneider KreuznachAngulon (Tronnier, 1930) with two outer negative menisci,[5] derived from the Goerz Dagor (Emil von Höegh, 1892);[10]: 92 and the Zeiss Topogon (Richter, 1933) with two outer positive menisci,[6] derived from the Goerz Hypergon (1900).[11]: 54–55 [3]: 118–119 These concepts were combined in a symmetric super-wide angle lens design using mirrored inverted telephoto lenses, as patented by Roosinov in 1946.[12]: 150
In 1950, Bertele designed the Wild Aviogon as a similar highly-symmetric wide-angle lens with a large angular coverage.[8] The following year, in 1951, Bertele designed a new Biogon with a 90° angle of view (Super Wide Angle).[9] The Biogon has been characterized as a simpler Aviogon.[12]: 151 Compared to the Aviogon, the Biogon removed a meniscus element and simplified the group ahead of the aperture.[9]
The first regular production Biogon lenses were produced from 1954 as the 4.5 / 21 mm for Contax, in 1954, 4.5 / 38 mm for Hasselblad Super Wide, and from 1955 to 1956 as the 4.5 / 53 mm and 4.5 / 75 mm for Linhof. The original patent spanned three different variants, each with a different maximum aperture: f/6.3, f/4.5, and f/3.4 lenses.[9]
Biogon (II) retrofocus development
AEG Weitwinkelobjektiv (1932), from DRP 620,538
Zeiss Sphaerogon by Merté (1935), from US 2,126,126
Angénieux Retrofocus (1950), from US 2,649,022
"Wide-angle lens" by Bertele (1952), from US 2,730,016[13]
The advent of the Biogon opened the way to more extreme wide-angle lenses. Bertele continued to develop his design, patenting an asymmetric wide-angle lens in 1952 that covered an astonishing 120° angle of view "and beyond, practically distortion free", by adding a strong negative meniscus front element to the Biogon design, showing influences from earlier fisheye lens designs, including the AEG Weitwinkelobjektiv (1932) and Zeiss Sphaerogon (1935, Willy Merté [de]), and the Angénieux retrofocus (1950).[13]
Examples
Since their introduction, lenses branded Biogon are usually approximately symmetrical ("semi-symmetrical") wide-angle design with a usable angle of view of 90° or more. At 90° the focal length is approximately half as long as the format's diagonal.
Well known camera manufacturers like Hasselblad have or had Biogon derived lenses to offer.
Grandagon, sold by Rodenstock for large format cameras[21]
Nikkor-O 2.1 cm f/4, sold by Nikon in both S rangefinder and F SLR mounts; with the Nikon F, the lens must be used with the mirror locked up.[22] This was replaced for the SLRs by the Nikkor-UD 20 mm f/3.5 retrofocus lens.[23] Nikon also sold the Nikkor-SW line of highly symmetric super-wide angle lenses for large format cameras.[24][25]
Fujinon-SW, a six-element, four-group design similar to the Super Angulon sold by Fujifilm for both its line of Fujica medium format rangefinder cameras (G690/BL, GM670, GSW6xx)[29] and large format cameras; an improved version (8e/4g) for large format cameras with slightly greater coverage was sold as the Fujinon-SWD.[30]
Günter Klemt patented the Super-Angulon for Schneider in 1954, citing Roosinov's 1946 patent; neither the Wild or Zeiss patents by Bertele were cited;[14] The Super Angulon design shares the same six-element, four-group construction with inner cemented doublets flanked by large negative meniscus elements with the Roosinov patent, diverging significantly from Bertele's Aviogon/Biogon designs. The Super-Angulon bears more similarities to the prior Angulon, designed by Albrecht Tronnier for Schneider in 1930 as another highly symmetric wide-angle lens with two cemented triplets.[5] A later 1957 patent by Klemt in collaboration with Karl Heinrich Macher, refining the Super Angulon design for Schneider, added citations to Bertele's patents.[31]
Wild continued to refine the Aviogon and filed for a patent on a simplified design in 1952;[32] that patent, in turn, was cited by Drs. Erhard Glatzel and Hans Schulz in their 1966 patent for the Hologon.[33]
^ abUS patent 2084309, Bertele, Ludwig, "Photographic lens system", issued 22 June 1937, assigned to Zeiss Ikon AG
^US Patent 2549159A, Ludwig Bertele, "Highly corrected photographic objective having four axially air spaced components", published April 17, 1951, assigned to Wild Heerbrugg AG
^ abcUS patent 1882530, Albrecht Wilhelm Tronnier, "Spherically chromatically and astigmatically corrected wide-angle lens with high aperture", issued October 11, 1932, assigned to Jos. Schneider & Co.
^ abUS patent 2031792, Robert Richter, "Anastigmatic objective for photography and projection", issued February 25, 1936, assigned to Carl Zeiss, Jena
^US patent 2516724, Michael Michaelovitch Roosinov, "Wide angle orthoscopic anastigmatic photographic objective", issued July 25, 1950
^ abUS patent 2734424, Ludwig Bertele, "Wide angle objectives of six air spaced components", issued 14 February 1956, assigned to Bertele, Ludwig
^ abcdUS patent 2721499, Bertele, Ludwig, "Five component wide-angle objective", issued 25 October 1955, assigned to Bertele, Ludwig
^"Fujica G690 Lenses". The 6x9 Photography Online Resource. Retrieved 22 March 2023.
^"Fujinon Professional Lenses"(PDF). Pacific Rim Camera, Reference Library. Fujifilm. November 1969. Retrieved 22 March 2023.
^US patent 2897725, Günter Klemt & Karl Heinrich Macher, "Optical system with large effective image angle", published August 4, 1959, assigned to Jos. Schneider & Co.
^GB patent 733308A, "Improvements in wide angle objectives", published July 6, 1955, assigned to Wild Heerbrugg AG
^DE patent 1241637B, Dr Erhard Glatzel & Dr Hans Schulz, "Dreilinsiges Weitwinkelobjektiv [Three-element wide-angle lens]", published June 1, 1967, assigned to Carl Zeiss AG